1. Field of the Invention
This invention relates generally to a braking apparatus of a vehicle, and more particularly to a braking apparatus for actuating a brake pedal of a vehicle in response to the braking of a towing-vehicle.
2. Description of Related Art
The following references describe the state of the art in the field of supplementary braking systems:
Hargrove, U.S. Pat. No. 5,431,253 describes a braking system for use on a towing vehicle and on a towed vehicle comprises a vacuum capture mechanism for capturing vacuum from a towing vehicle. A vacuum delivery mechanism is provided for delivering vacuum to a towed vehicle. A switch mechanism is also provided for allowing controlled transfer of vacuum to a towed vehicle. A vacuum reception mechanism is coupleable with the vacuum delivery mechanism for receipt of vacuum. An air pressure mechanism is adapted to be coupled to a towed vehicle for generating air pressure when actuated. A ram mechanism is coupled to the air pressure mechanism for depressing a brake pedal of a towed vehicle when the air pressure mechanism is actuated. A vacuum switch mechanism is coupled to the vacuum reception mechanism. The vacuum switch mechanism has one orientation for actuating the air pressure mechanism upon receipt of vacuum. A check valve switch mechanism is coupled to the vacuum switch mechanism and adapted to be coupled to a brake vacuum system of a towed vehicle for receipt of vacuum therefrom.
Wittkop et al., U.S. Pat. No. 5,031,729 describes a braking apparatus that applies the brakes of a towed vehicle in response to braking of the towing vehicle. An air compressor driven by the motor of the towing vehicle supplies compressed air to a compressed air storage tank with a pneumatic line extending from the compressed air storage tank rearwardly to a braking assembly which is positioned in the passenger compartment of the towed vehicle. The braking assembly is adjustable and includes a rod positioned between the steering wheel and the brake pedal of the towed vehicle and is secured to both. A pneumatic control device is connected to the pneumatic line to receive a signal therethrough to actuate the braking assembly through an actuation device such as a pneumatic piston to exert pressure to expand the length of the bar and apply the brakes of the towed vehicle. An air release valve in the bar assembly can exhaust air from the pneumatic piston responsive to cessation of compressed air being supplied through the pneumatic line to facilitate immediate release of the brakes of the towed vehicle.
Rossigno, U.S. Pat. No. 3,790,807 describes a solenoid operated control valve for establishing an operational pressure differential in a servomotor located in a trailer to activate the wheel brakes of the trailer in response to an operational electrical signal derived from corresponding hydraulic actuation of the wheel brakes of a tow vehicle.
Lichter, U.S. Pat. No. 5,465,813 describes a device for applying the brake of a towed vehicle when towed by a towing vehicle equipped with an air brake system having a power brake operator operative to supply operating air under pressure to apply a brake on the towing vehicle and also having a reservoir of operating air under pressure. The device is connected to the brake pedal of the towed vehicle. It comprises a first piston-cylinder assembly with a spring for urging the piston therein to an advanced position, and a second piston-cylinder assembly having a spring urging the piston therein to a retracted position. The brake on the towed vehicle is applied only when one of the pistons is advanced. An air line supplies air from the reservoir to the first piston-cylinder assembly to urge the piston to a retracted position against the action of the spring. The brake of the towed vehicle is applied when the piston in the first piston-cylinder assembly is moved to an advanced position by the spring therein in response to a loss of pressure in the reservoir. The brake of the towed vehicle is also applied when the piston in the second piston-cylinder assembly is moved against the spring force to its advanced position by operating air under pressure from the power brake operator when the power brake operator applies the brakes of the towing vehicle.
Avery et al., U.S. Pat. No. 5,213,396 describes a towed motor vehicle brake integrated between a towing and a towed vehicle, capable of applying the brakes of the towed vehicle. The structure of a towing hitch linkage deflects somewhat when it experiences tension or compression. A sensing device, preferably consisting of a hydraulic cylinder and an attached activating rod, grounded to a rotating lever connecting to the towed vehicle, senses compression of the deflecting portion of the linkage and activates the brakes of the towed vehicle to reduce the compressive forces. The tow brake requires no modification of the towed vehicle except allowing an interface with the towed vehicle's braking system. This provides flexibility of use with a variety of towed vehicles and ease of attachment and detachment.
Harness, U.S. Pat. No. 5,411,321 describes a system for selectively applying the brakes of a towed vehicle by controls in the towing vehicle; the system including a portable air compressor and a pneumatic cylinder that can be rapidly installed by attaching to a support structure on the floor of the driver's cockpit in the towed vehicle; the piston of the cylinder being attached to the brake pedal; and a three-way solenoid valve to permit or not to permit the admission of compressed air to the cylinder.
The prior art teaches braking devices that actuate a brake pedal of a towed vehicle in response to a signal from a towing vehicle. However, the prior art does not teach a cable connection that enables a brake actuator to actuate the brake pedal from any location within the towed vehicle. The present invention fulfills these needs and provides further related advantages as described in the following summary.